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The aim of this work is to analyze the usefulness of Sr3(PO4)2 as a potential antibacterial agent in fast-degradable polymer coatings. The Ti implant was anodized and then covered by a poly(adipic anhydride) layer blended with Sr3(PO4)2 particles by dip coating. The average size of the particles was 450 nm ± 53 nm (Zetasizer analysis), and phase analysis (X-ray diffractometer) showed mainly crystalline phases. Surface morphology and surface roughness were analyzed by scanning electron microscopy with energy dispersive X-ray (EDX). The oxide layer thickness on the implant surface was between 4.57 μm and 8.09 μm. The polymer layer with Sr3(PO4)2 particles was determined by confocal microscopy, and the average thickness was 25 μm. The contact angle of the anodized Ti implant alone was 37.3° ± 9.9° and decreased with time up to 20° after 1900s. After 1 h of implant immersion in Ringer solution, 42.15% of the Sr compound loaded in the polymer layer was released (determined by inductively coupled plasma atomic emission spectrometry (ICP-AES)). Fast degradation of the polymer caused 65.21% of the loaded Sr compound to be released from the implant surface after 24 h. The concentration of Sr3(PO4)2 was enough to significantly inhibit the adhesion of Staphylococcus aureus ATCC 25923 bacteria on the implant surface. The implant surface is cytocompatible with osteoblast-like MG-63 cells. The preliminary results of hybrid coating analysis showed that Sr3(PO4)2 may be used as an alternative ceramic material for the formation of a functional layer for orthopedic applications.

Bones are the functional tissue, to provide structural support, protect vital organs, store minerals, helps in multi-directional motion and bear load of our body. Fracture of bones, in which continuity of bone tissue breaks, which occurred due to trauma (high intensity impact) and over stressing are treated with help of bone implants. Bone implants are fabricated through biomaterials which are categorized as as: (a) first generation, (b) second generation and (c) third generation biomaterials. First generation implants are bioinert, second generation implants are biodegradable, bioinert and bioactive. Third generation implants focuses on stimulating specific cellular response at molecular level along with the properties of second generation. Bone tissue engineering (BTE) is responsive for the evolution of third generation implants, where the main focus is to create the environment which helps to stimulate the cell response in direction of bone regeneration. This aim is achieved with engineered tissue implant which includes: (a) scaffold for architectural support & cell homing, (b) osteogenic cells and (c) signaling growth factors. Tissues in human body are the 3D repeating unit cells also called as extra cellular matrix (ECM). Similarly scaffold is the artificial 3D porous structure of biomaterials (ceramics, metals and polymers) which mimic those 3D repeating unit cells or ECM. Scaffold is a backbone or fundamental unit of BTE. Success of scaffold decides the success of engineered bone tissue implant. This review summarizes the factor influencing BTE, factor involved in selection of material for scaffold fabrication and trending fabrication methods for BTE scaffolds.

Актуальність. Переломи проксимального відділу плечової кістки (ПВПК) становлять 5–6 % усіх пошкоджень довгих кісток скелета людини. З метою збільшення жорсткості фіксації хірургічне лікування накістковими пластинами доповнюють різними ало- або автотрансплантатами, імплантатами, а також кістковим цементом (тип В і С за AO/ОТА). Авторами як альтернативний імплантат для заміщення дефектів спонгіозної кістки і підтримки кісткових фрагментів головки плечової кістки пропонується використовувати полілактид (PLA) Ingeo™ Biopolymer 4032D. Мета роботи: провести порівняльний аналіз напружено-деформованого стану системи «кістка — імплантат» накісткового остеосинтезу пластиною PHILOS із солідними і пористими 3D-імплантатами з PLA. Матеріали та методи. Для математичного моделювання і порівняльного вивчення напружено-деформованого стану системи «кістка — імплантат» у разі накісткового остеосинтезу змодельована пластина з кутовою стабільністю PHILOS (з нержавіючої сталі), трьохфрагментарний перелом ПВПК з використанням або 2 солідних, або 2 пористих імплантатів PLA з ґратчастими порожнинами. Як об’єкт для побудови плечової кістки використана композитна модель № 3404 лівої плечової кістки фірми Sawbones (Europe AB, Мальме, Швеція), для всіх матеріалів у моделюванні — ізотропна лінійна модель з однаковими фізико-механічними характеристиками для всіх матеріалів. Як інструмент дослідження застосовувався метод кінцевих елементів, реалізований пакетом прикладних програм Ansys. Результати. Порівняльна оцінка впливу форми імплантатів PLA для двох розрахункових схем виконана за допомогою порівняння еквівалентних напружень за Мізесом і полів деформацій для моделей, різних елементів з’єднання і частин системи «кістка — імплантат». Встановлено, що перерозподіл полів напружень в елементах моделі не призводить до її руйнування. Моделі та всі їх елементи задовольняють вимогам міцності. Заміна циліндричного солідного 3D-імплантата на модифікований пористий 3D-імплантат для підтримки суглобової поверхні головки плечової кістки в умовах остеопорозу при остеосинтезі трьохфрагментарного перелому ПВПК накістковою пластиною PHILOS не знижує жорсткості фіксації. Висновки. Порівняльний аналіз напружено-деформованого стану системи «кістка — імплантат» накісткового остеосинтезу пластиною PHILOS з солідними і пористими 3D-імплантатами з PLA показав, що зміна форми імплантатів у розглянутому діапазоні навантаження не впливає на жорсткість системи. Поля деформацій і напружень для розглянутих моделей практично збігаються між собою. У пластині PHILOS та у модифікованих пористих 3D-імплантатах PLA відбувається зменшення напружень на 5 та 4 МПа відповідно. Заміна циліндричної солідної форми 3D-імплантатів PLA на модифіковану пористу є доцільною, тому що дозволяє збільшити площу контакту імплантата PLA з кісткою, а його порожнини можливо використовувати для наповнення плазмою, насиченою тромбоцитами.

Implant-related infections are serious complications after bone surgery and can compromise the intended functions of artificial implants, leading to surgical failure and even amputation in severe cases. Various strategies have been proposed to endow bone implants with the desirable antibacterial properties, but unfortunately, most of them inevitably suffer from some side effects detrimental to normal tissues. In this study, a multifunctional bone implant is designed to work in conjunction with sequential photothermal mediation, which can deliver antibacterial therapy (lt;50 °C) in the early stage and foster bone regeneration (40-42 °C) subsequently. Black phosphorus nanosheets (BPs) are coordinated with zinc sulfonate ligand (ZnLsub2/sub), and the ZnLsub2/sub-BPs are integrated into the surface of a hydroxylapatite (HA) scaffold to produce ZnLsub2/sub-BPs@HAP. In this design, BPs produce the photothermal effects and ZnLsub2/subincreases the thermal sensitivity of peri-implant bacteria by inducing envelope stress. The biosafety of the antibacterial photothermal treatment is improved due to the mild temperature, and furthermore, gradual release of Znsup2+/supand POsub4/subsup3-/supfrom the scaffold facilitates osteogenesis in the subsequent stage of bone healing. This strategy not only broadens the biomedical applications of photothermal treatment but also provides insights into the design of multifunctional biomaterials in other fields.

BACKGROUND: Reconstruction of extensive defects to bone tissue is one of the important problems of orthopedics and traumatology. Especially in acuteis, the problem is associated with the restoration of bone tissue in conditions of its deficiency in pediatric patients. AIM: The aim of the study is to analyze modern methods of surgical treatment in children with extensive bone tissue injuries based on the published literature. MATERIALS AND METHODS: Our report presents a review of the literature of methods of surgical treatment of extensive bone defects. The literature search was carried out in several databases such as PubMed, ScienceDirect, E-library, GoogleScholar for the period from 2005 to 2020, using the keywords given below. As a result of the search, 105 foreign and 37 domestic sources were found. After exclusion, 56 articles were analyzed, all presented works were published in the last 15 years. RESULTS: The gold standard for replacing bone defects is still the use of autografts, including the use of technologies on a vascular pedicle. Various types of xenografts and allografts of bone tissue are increasingly being replaced by various kinds of synthetic implants. CONCLUSIONS: To date, there is no single generally accepted standard for the surgical treatment of extensive bone defects. The option of surgical treatment of extensive bone tissue defects using tissue-engineered bone implants with axial blood supply seems to be extremely interesting and promising.

This article presents the surface modification of iron Fe (110) surfaces with Poly-L-Lysine (PLL) with the aim of preparing carbonyl iron bone implants which are less corrosive and more compatible with fibroblast cells. The cytocompatibility of modified surfaces with commercially available α-PLL and electrodeposited ε-PLL was compared by combination of DFT computational simulations with experimental electrochemical and cell adhesion studies to obtain “smart” surface application. Experimental study of fibroblasts adhesion showed better viability of cells on ε-PLL than on α-PLL after modification of Fe surfaces as “smart” surfaces to obtain a different hydrophobicity. The porosity of Fe (110) prevented direct measurements of contact angle and therefore surface hydrophobicity was simulated with calculation of adsorption energies for Fe with both α-/ε- PLL structures. This technique was also employed to calculate the interaction of O-H bonds at the surface. The corrosion potential of Fe (110) with superficially modified ε-PLL was shifted by 0.088V compared to the bare iron surface, thus indicating a stronger resistance to corrosion. The results suggest that modification of Fe surface with ε-PLL has a more pronounced effect on cellular growth on this implant and that the slightly hydrophobic character of ε-PLL leads to better cell adhesion ability.

Silk, seen as a material, is a fiber made from silkworm cocoons and spiders. They have standard structural components and hierarchical structures. Different manufacturing techniques allow obtaining silk in films, fibers, hydrogels, microspheres, and sponges. We can tune the properties through the structure of secondary proteins. The paper explores the application in biomedical, optics, and electronic fields by analyzing the technological trend.

Titanium (Ti) has been used in metallic implants since the 1950s due to various biocompatible and mechanical properties. However, due to its high Young’s modulus, it has been modified over the years in order to produce a better biomaterial. Tantalum (Ta) has recently emerged as a new potential biomaterial for bone and dental implants. It has been reported to have better corrosion resistance and osteo-regenerative properties as compared to Ti alloys which are most widely used in the bone-implant industry. Currently, Tantalum cannot be widely used yet due to its limited availability, high melting point, and high-cost production. This review paper discusses various manufacturing methods of Tantalum alloys, including conventional and additive manufacturing and also discusses their drawbacks and shortcomings. Recent research includes surface modification of various metals using Tantalum coatings in order to combine bulk material properties of different materials and the porous surface properties of Tantalum. Design modification also plays a crucial role in controlling bulk properties. The porous design does provide a lower density, wider surface area, and more immense specific strength. In addition to improved mechanical properties, a porous design could also escalate the material's biological and permeability properties. With current advancement in additive manufacturing technology, difficulties in processing Tantalum could be resolved. Therefore, Tantalum should be considered as a serious candidate material for future bone and dental implants.

Component alignment in total knee arthroplasty is a determining factor for implant longevity. Mechanical alignment, which provides balanced load transfer, is the most common alignment strategy. However, a retrospective review found that varus alignment, which could lead to unbalanced loading, can happen in up to 18% of tibial baseplates. This may be particularly burdensome for cementless tibial baseplates, which require low bone-implant micromotion and avoidance of bone overload to obtain bone ingrowth. Our aim was to assess the effect of varus alignment on the bone-implant interaction of cementless baseplates. We virtually implanted 11 patients with knee OA with a modern cementless tibial baseplate in mechanical alignment and in 2° of tibial varus alignment. We performed finite element simulations throughout gait, with loading conditions derived from literature. Throughout the stance phase, varus alignment had greater micromotion and percentage of bone volume at risk of failure than mechanical alignment. At mid-stance, when the most critical conditions occurred, the average increase in peak micromotion and amount of bone at risk of failure due to varus alignment were 79% and 59%, respectively. Varus alignment also resulted in the decrease of the surface area with micromotion compatible with bone ingrowth. However, for both alignments, this surface area was larger than the average area of ingrowth reported for well-fixed implants retrieved post-mortem. Our findings suggest that small varus deviations from mechanical alignment can adversely impact the biomechanics of the bone-implant interaction for cementless tibial baseplates during gait; however, the clinical implications of such changes remain unclear.

This work deals with the problem of synthesis and investigation of the structure and properties of polymer calcium phosphate biopolymer suspensions, their use to obtain film samples containing drugs, and the study of the kinetics of drug release from the polymer matrix. The compositions were synthesized using the method of mechano-acoustic activation. The use of the mechano-acoustic activation technique and ultrasonic dispersion makes it possible to synthesize calcium phosphate compounds in aqueous media, to modify the synthesized products with drugs and bioactive substances, and to form biocompositions for the manufacture of bone implants.

Porous degradable metallic biomaterials are attracting considerable attention as promising bone implant materials. Recently, the interest in developing new biomaterials with enhanced performance stimulates the widespread development of fabricating techniques for porous metals. In this work, the recent progress and novel trends on preparation methods of metallic foams for biomedicine were systematically reviewed. The common synthesis methods for porous Mg, Fe, Zn, and their alloys intended for orthopedic applications are comprehensively discussed and compared. The advantages and disadvantages of relevant manufacturing strategies are evaluated. While the modern techniques enable fabrication of complex porous structures and customized shapes, the cost-effective and easy controllable approach are major benefits of traditional methods. Main structural characteristics and properties of biomaterials fabricated using different routes are also presented. Furthermore, the future research directions and current challenges are mentioned. The ambition of this review article is to provide useful guidelines for researchers to choose suitable manufacturing technique to prepare materials with desired structural topology and mechanical, and degradation properties.

Mg and its alloys have been comprehensively studied and show huge potential for clinical orthopedic applications. However, balancing the mechanical strength and corrosion resistance of alloys is still a challenge. In light of this, micro-level contents of Zn and Ca were added to pure Mg to fabricate a Mg-2Zn-0.05Ca microalloy to expectedly enhance the mechanical strength and concurrently improve the corrosion resistance. The characteristics of the rolled Mg-2Zn-0.05Ca microalloy were explored using optical microscopy, X-ray diffraction, and tensile tests. The corrosion behavior and mechanical strength loss were explored using electrochemical and immersion tests. The effects of the microalloy extract on the proliferation, adhesion, and osteogenic differentiation of MC3T3-E1 cells were systematically studied. Moreover, implantations were done in femoral condyles of rabbits to study the degradation properties, osteogenic effect, mechanical strength loss, and biosafety of the microalloy. The ultimate tensile strength and yield strength of the rolled microalloy were found to be significantly elevated to 257 ± 2.74 and 237.6 ± 8.29 MPa, respectively. The microalloy showed a stable and gradual strength loss during degradation, both in vivo and in vitro. Concurrently, the microalloy exhibited improved corrosion resistance ability and especially, in vivo, the rolled microalloy exhibited a comparable degradation rate to that of rolled pure Mg within the initial 12 weeks of implantation. Additionally, the microalloy promoted osteogenesis, both in vitro and in vivo, and no short- and long-term toxicities of the microalloy were observed in rabbits. This study suggested that the rolled Mg-2Zn-0.05Ca microalloy effectively balanced the mechanical strength and corrosion resistance and showed potential application as bone implants.

Titanium implants have been widely used as one of the most effective treatments of bone defects. However, the lack of osteogenesis and bacteria-resistant activities result in high infection and loosening rates of titanium implants. Anodic oxidation could easily construct titanium dioxide nanotubes (TNTs) array on the surface of titanium, and the rough surface of TNTs is beneficial to the growth of osteoblast-related cells on the surface. And TNTs could be excellent drug carriers because of their single-entry tubular hollow structure. In this review, we aim at detailing the application of TNTs as drug carriers in the field of bone implants. Starting from the topography of TNTs, we illustrated the biological activity of the TNTs surface, the drugs for loading in TNTs, and the controlled and responsive release strategies of drug-loaded TNTs, respectively. At the end of this review, the shortcomings of TNTs as the drug carrier in the field of bone implants are discussed, and the development direction of this research field is also prospected.

Biomedical titanium alloys with elastic moduli close to that of cortical bone have gained great attention in the field of bone implantation. A low modulus is desirable in an implant to prevent stress shielding, which usually leads to critical clinical issues, such as bone resorption and implant loosening. The use of β-type titanium with nontoxic alloying elements, such as niobium, as a novel candidate of implant material for replacing failed hard tissues has shown great potential. This review describes a titanium implant application alloyed with niobium and the mechanical properties and bioactivity of various titanium alloys sintered at different temperatures.

A strategy is proposed for developing combined technologies for sterilizing bone implants. The procedure is based on exposure to X- and γ-ray radiation and fast electron beams, in combination with preliminary ozone treatment to reduce the absorbed dose while ensuring the sterility of bioimplants and creating modern health-saving technologies.

Tantalum has unique advantages as a biomaterial for repairing bone defects due to its outstanding bioactivity, excellent corrosion resistance, and mechanical properties. Ideal implants for bone repair should be of good biocompatibility and bioactivity, as well as ability to simulate the microstructure and mechanical environment of human bone tissues. Additive manufacturing can facilitate freedom of design for the macrostructure/microstructure of bone implants with controlled mechanical properties; thus, this method has great potential. Additively manufactured tantalum implants provide a novel alternative for bone repair and are gaining increasing attention. This systematic review aims to comprehensively summarize the subsistent evidence from physicochemical, cellular, animal, and clinical studies on additively manufactured tantalum implants in repairing bone defects, for the first time. This work may provide researchers an essential grasp on the advances of additively manufactured tantalum implants. Impact statement Tantalum has unique advantages as a biomaterial. Additive manufacturing facilitates design freedom and additively manufactured tantalum is a novel alternative for bone repair. Studies on additively manufactured tantalum progress greatly, while no review summarizing the progresses was published.

Millions of people suffer from bone loss and diseases each year, which give rise to bone-related medical treatments. Multi-material coatings composed of Silicon Substituted Hydroxyapatite (Si-HA) and Silver Substituted Hydroxyapatite (Ag-HA) potentiated its usage as an ideal bone implant material with favourable biological response and antibacterial properties, respectively. Each patient has different conditions (e.g. bone ages, bone density, position, and infection status) and specific bone implant requirement, thus requiring specific designs of Si-HA and Ag-HA bone implant material ratios. In this paper, a recommender system which took advantage of Wide&Deep recommendation architecture and DenseNet architecture was provided and a semi-supervised training process was utilized to recommend appropriate bone implant material ratio (Si-HA:Ag-HA) for each patient to improve the bone disease treatment and recovery. The proposed recommendation system could achieve high accuracy ( $$92.2\%$$ ) and efficiency (using only $$10\%$$ of labeled data) on test dataset, which could be potentially utilized in future clinical usages and provide doctors with decision support to make better clinical decisions.

Magnesium based materials are considered promising biodegradable metals for orthopedic bone implant applications as they exhibit similar density and elastic modulus to that of bone, biodegradability, and excellent osteogenic properties. The use of Mg based biomaterials eliminates the limitations of currently used implant materials such as stress shielding and the need for the second surgery. Recently, the development of Mg-based implants has attracted significant attention. Additive manufacturing is one of the effective techniques to develop Mg based implants. Additive manufacturing which could be named 3D printing is a transformative and rapid method of producing industrial parts with in the acceptable dimensional range. Therefore, recent investigations have tried to apply this method for the development of Mg-based implants. This state-of-the-art review focuses on the additive manufacturing of Mg biodegradable materials and their in-vitro corrosion and degradation, and mechanical properties. The future directions to develop Mg biodegradable materials are reported through summarization of current achievements.

Bone loss and significant acetabular defects remain one of the major problems in revision hip arthroplasty. A promising material for grafting of bone defects can be materials based on allogeneic bone after various types of processing, combining optimal properties for osteoregeneration. Objective. To analyze the results of acetabular reconstruction with bone implants «OMS-A» in the case of revision arthroplasty. Methods. The results of examination and treatment of 57 patients (33 women and 24 men) were analyzed. The patients’ age at the time of hospitalization ranged from 24 to 81 years. Patients were diagnosed on the basis of a combination of clinical ma­nifestations of the disease, laboratory data, radiography, computed tomography with 3D reconstruction. According to the classification of W. G. Paprosky, the largest group consisted of type I defects — 25 patients (44 %), II — 13 (23 %), III — 19 (33 %). For the reconstruction of the acetabulum, 21 patients (37%) we used fragmented cortical-cancellous pieces (CGP), 28 (49 %) — volumetric bone implants (OCI), 8 (14 %) — a combination of CGP and OCI. All patients underwent revision hip arthroplasty with an anterolateral approach according to Harding. The resulting acetabular defect was tightly filled with an allografts. Results. X-ray and G. A. Gie results were assessed as good in 36 patients (63 %), satisfactory — in 14 (25 %). The manifestations of infection associated with the use of bone implants «OMS-A» have not been determined. The necessity for repeated surgery in order to restore the acetabulum occurred in 7 patients (12 %). Conclusions. Тhe clinical efficiency of bone implants «OMS-A» for the reconstruction of the acetabulum according to the classification of W. G. Paprosky was: with type I defect — 92 %; with type I and type defect — 92.3 %; with type II and type defect — 78.9 %.

The only alloy currently utilized for additive manufacture of bone implants, Ti–6Al–4V, has a high elastic modulus and bioinert surface, potentially inducing stress shielding and hindering osseoint...

Bone implants capable to create an electrical stimulus for bone tissue regeneration under the influence of an external magnetic field are considered. A promising method for generating local electric fields is the use of magnetoelectric (multiferroic) micro- and nanoparticles, being polarized under the action of an external magnetic field, creating electric fields comparable in amplitude to endogenous ones. Of practical interest are composite magnetoelectric particles consisting of a ferrimagnetic core and a piezoelectric shell brought into close mechanical contact. The paper presents the results of modeling the magnetoelectric effect in a composite particle, fabrication of composite particles with cobalt ferrite as a magnetostrictive core, and considers the issues of the chemical interaction of phases.

Bioadaptability, proposed earlier to accentuate the biomaterial-host interactivity, incites the development of adaptable biomaterials. Esser-Kahn et al. 3 recently reported a biomaterial that can self-adapt to its mechanical environment as potential bone implants. Such endeavors allow “precise bioadaptability” for fueling precision medicine.

Replacement and regeneration of damaged bone, particularly for those defects with critical size, are still major challenges in orthopaedic surgery. The conventional bone implants, normally with poor internal architecture design, may cause significant issues owing to the mechanical and structural mismatches between target bone and the implants. In this work, as inspired by hierarchical natural bone, for the first time, we developed hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) scaffolds with three-level hierarchical structures across macro to nano scale using combined 3D printing (3DP) and freeze casting routines. It is clear these hierarchical porous scaffolds significantly enhance cell penetration (over 7 times) while maintaining cell proliferation ability. With three levels of hierarchies, the overall mechanical behaviour of the scaffolds can be tailored to be comparable to general cancellous bone (ranging from 1 to 6 MPa), demonstrating great potential for practical applications. Additionally, the combination of nanoindentation and mechanics model makes it possible to predict the mechanical behaviour of scaffolds at micro and macro scales.

Implant loosening is still the major form of the failure of artificial joints. Herein, inspired by the operculum of the river snail, we prepared a novel bionic micro/nanoscale topography on a titanium surface. This bionic topography promoted early cell adhesion through up-regulating the expression of ITG α5β1 and thus accelerated the following cell spreading, proliferation, and differentiation. Moreover, a miR-21 coating, which promoted the angiogenic differentiation of MSCs, was fabricated on the bionic topography. Benefiting from both bionic micro/nanoscale topography and miR-21, blood vessel growth and bone formation and mineralization around the implant, as well as bone-implant bonding strength, were significantly improved. Collectively, the present study highlights the combination of the bionic micro/nanoscale topography and miR-21 on promoting cell adhesion and angiogenic differentiation and improving in vivo angiogenesis and bone-implant osseointegration. This work provides a new train of thought propelling the development of implants for potential application in the orthopedics field.

As two promising biomaterials for bone implants, biomedical metals have favorable mechanical properties and good machinability but lack of bioactivity; while bioceramics are known for good biocompatibility or even bioactivity but limited by their high brittleness. Biocermets, a kind of composites composing of bioceramics and biomedical metals, have been developed as an effective solution by combining their complementary advantages. This paper focused on the recently studied biocermets for bone implant applications. Concretely, biocermets were divided into ceramic-based biocermets and metal-based biocermets according to the phase percentages. Their characteristics were systematically summarized, and the fabrication methods for biocermets were reviewed and compared. Emphases were put on the interactions between bioceramics and biomedical metals, as well as the performance improvement mechanisms. More importantly, the main methods for the interfacial reinforcing were summarized, and the corresponding interfacial reinforcing mechanisms were discussed. In addition, the in vitro and in vivo biological performances of biocermets were also reviewed. Finally, future research directions were proposed on the advancement in component design, interfacial reinforcing and forming mechanisms for the fabrication of high-performance biocermets.

The capability to hinder microbial growth on the implant surfaces is of great interest in medical applications. This paper presents our study on the synthesis of zeolite/silver-graphene oxide (Zeo/...

Overall long-term success of metallic bone implant is mainly governed by the two key factors osseointegration and antibacterial function. Bioceramic hopeite coatings have been proven effective for ...

Diaphyseal defects of canine tibia bones were replaced with bioactive cylindrical mesh implants made of Ti–6Al–4V titanium alloy. Bone−implant units were cut with a precision cutter using abrasive cutting discs (thickness, 0.76 mm; rotational speed, 2000 rpm; feed rate, 12 mm/min for sample 1 and 5 mm/min for samples 2–4). Tissues were found to suffer thermal damage at a disc feed rate of 12 mm/min; 72.6% of tissues in the projection of the defect cavity were found to be unsuitable for histological examination. At a feed rate of 5 mm/min, thermal damage or significant mechanical damage to the tissues was not observed. Thus, at the stage of preparation of samples of titanium–containing bone−implant units for the assessment of osseointegration, the degree of tissue preservation, under otherwise identical conditions, depends on the cutting tool feed rate.

PurposeThe objective of this paper is to identify suitable lattice structure patterns for the design of porous bone implants manufactured using additive manufacturing.Design/methodology/approachThe study serves to compare and analyse the mechanical behaviours between cubic and octet-truss gradient lattice structures. The method used was uniaxial compression simulations using finite element analysis to identify the translational displacements.FindingsFrom the simulation results, in comparison to the cubic lattice structure, the octet-truss lattice structure showed a significant difference in mechanical behaviour. In the same design space, the translational displacement for both lattice structures increased as the relative density decreased. Apart from the relative density, the microarchitecture of the lattice structure also influenced the mechanical behaviour of the gradient lattice structure.Research limitations/implicationsGradient lattice structures are suitable for bone implant applications because of the variation of pore sizes that mimic the natural bone structures. The complex geometry that gradient lattice structures possess can be manufactured using additive manufacturing technology.Originality/valueThe results demonstrated that the cubic gradient lattice structure has the best mechanical behaviour for bone implants with appropriate relative density and pore size.

Aim: Additively manufactured (3D printed), stainless steel implants were coated with dexamethasone using gelatin, chondroitin sulfate for use in bone graft surgeries. Materials & methods: The drug and polymers were deposited on the implants with a rough surface using a high precision air brush. The gelatin-chondroitin sulfate layers were cross-linked using glutaraldehyde. Results: The drug content uniformity was within 100 ± 5%, and the thickness of the polymer layer was 410 ± 5.2 μm. The in vitro release studies showed a biphasic pattern with an initial burst release followed by slow release up to 3 days. Conclusion: These results are very promising as the slow release implants can be further tested in vivo in large animals, such as cattle and horses to prevent the inflammatory cascade following surgeries.

The present study addresses the issue of infection on and around titanium orthopaedic implants by modifying the Ti6Al4V implant surface with titania nanotubes via electrochemical anodisation follow...

Magnesium (Mg) alloy shows great potential as bone implant owing to its favourable biocompatibility and degradability. In the present work, bioglass-reinforced Mg-based composite was manufactured v...

Hydroxyapatite (HAp) made of capiz shell has been successfully coated onto stainless steel 316L substrate using electrophoretic deposition (EPD) method. In this study, three variations were applied, they were the voltages of 25 V and 50 V, the withdrawal speeds of 0.1 mm/s, 0.5 mm/s, and 1 mm/s, and the sintering temperatures of 750, 850, and 950 °C. These variations were applied to determine the differences in morphology and crystal structure of the layers so that the most suitable result was obtained as a candidate for the bone implant. Characterization was done by Scanning Electron Microscope and X-Ray Diffractometer. The EPD process and the application of sintering temperature eliminated the phase of B type apatite carbonate which made the purity of the HAp layer higher. The SEM results show that the layer was more homogeneous and free of cracking at a voltage of 50 V and the withdrawal speed of 0.1 mm/s. The layer density was higher as the voltage and sintering temperature increased. Higher sintering temperature also made the layer more homogeneous, but at 950 °C, stainless steel 316L substrate underwent a phase transformation which caused the decreasing of the purity of the HAp layer. The best results were obtained by applying a50 V voltage, a withdrawal speed of 0.1 mm/s, and a sintering temperature of 850 °C.

A biologically - validated biodegradable material must comfortably stay in the physiological environment it is placed in, before finally disappearing over the intended period of time with adequate rates of degradation. The primary objective and utility of such a material is to eliminate the requirement of secondary surgery in applications involving bone implants. In recent decades, biodegradable alloys have exhibited enhanced biocompatibility, and improved mechanical and biodegradation properties. This has generated renewed interest in the design of bone implants made up of such materials that can successfully support fractured bone till the culmination of the healing process. However, striking a balance between two seemingly conflicting requirements, namely - sustaining the strength of the implant till the bone acquires the desired strength of its own, and allowing the implant to keep losing strength with its gradual degradation – may be rather complex. To manage this, different healing phases and the associated bone - biodegradable implant interface mechanobiology needs to be focused upon. An adequate and/or optimal design of the implant is based on mechanical properties, degradation rates of implant and bone-biodegradable implant interface interactivity. This review mainly focuses on bone - biodegradable implant interface with due consideration accorded to the mechanical properties, degradation rates and healing process in a standard duration.

Purpose The aim of this study was to assess the biomechanical properties of intact vertebra augmented using a local osteo-enhancement procedure to inject a triphasic calcium sulfate/calcium phosphate implant material. Methods Twenty-one fresh frozen human cadaver vertebra (Th11–L2) were randomized into three groups: treatment, sham, and control (n = 7 each). Treatment included vertebral body access, saline lavage to displace soft tissue and marrow elements, and injection of the implant material to fill approximately 20% of the vertebral body by volume. The sham group included all treatment steps, but without injection of the implant material. The control group consisted of untreated intact osteoporotic vertebra. Load at failure and displacement at failure for each of the three groups were measured in axial compression loading. Results The mean failure load of treated vertebra (4118 N) was significantly higher than either control (2841 N) or sham (2186 N) vertebra (p p Conclusions This biomechanical study shows that a local osteo-enhancement procedure using a triphasic implant material significantly increases the load at failure and displacement at failure in cadaveric osteoporotic vertebra.

Tantalum is a refractory metal with a melting point of 2996°C but it offers outstanding biocompatibility for bone implant applications. In this study, the selective electron beam melting (SEBM) process was used for the first time to fabricate both dense and fine lattice tantalum structures. The use of 90-ppm-oxygen Ta powder for SEBM ensured excellent ductility of the as-printed fine Ta lattice implants with strut diameter of just 350 μm. The as-printed dense Ta samples (99.90%) achieved tensile ductility of 45% compared with the minimum requirement of 25% by ISO 13782 and the reported 2% fabricated by SLM using 1800-ppm-oxygen Ta powder. Since 2016, 27 clinical applications have been achieved in China using the custom-designed and SEBM-printed Ta implants by the authors of this study. All these Ta implants (mostly Ta lattice structures) have performed satisfactorily in patients’ bodies so far. Three selected clinical applications, Ta lattice hip, fibula and femur implants, are briefly discussed in this article.

After more than 5 decades of research, the failure of bone implants is still poorly understood. The aging population makes it increasingly urgent to solve this issue. Among the reasons for failure, catastrophic brittle fracture can be directly related to the implant material and fabrication and deserves more attention. Indeed, clinically available implants do not sufficiently reproduce the hierarchical and heterogeneous microstructural organization of our natural bones, ultimately failing at replicating their mechanical strength and toughness. Nevertheless, recent advances in additive and advanced manufacturing have opened new horizons for the fabrication of biomimetic bone implants, challenging at the same time their characterization, testing, and modeling. This critical review covers selected recent achievements in bone implant research from a materials standpoint and aims at deciphering some of the most urgent issues in this multidisciplinary field. Nanyang Technological University Accepted version H. L. F. acknowledges financial support from Nanyang Technological University with the Start-Up grant M4082382.050.

OBJECTIVE The aim: To study was to use mathematical modeling in assessing the stress-strain state of the bone-implant system during plate osteosynthesis with a PHILOS plate of a proximal humerus fracture with polylactic acid implants. PATIENTS AND METHODS Materials and methods: Two bone-implant systems with a three-fragment humerus fracture according to the Neer classification (type 11-C1 according to the AO / ASIF classification) were selected for the study, one of which was with additional reinforcement of the head fragment with two polylactic acid implants (PLA - polylactide Ingeo™ Biopolymer 4032D). Sawbones (Europe AB, Malmo, Sweden) built the humeral model on 3D scanning of the composite model № 3404 of the left humerus. RESULTS Results: A comparative analysis of the obtained results of mathematical modeling of the stress-strain state of the bone-implant systems showed that with given constraints (hand abduction to 90°), the use of two polylactic acid implants can reduce the stress in the plate and screws, respectively, by 11% and 6% . CONCLUSION Conclusions: The use of polylactic acid implants during osteosynthesis of three- and four-fragment fractures of the proximal humerus, especially in the case of osteoporosis, allows providing for the reinforcement of metal structures and supporting of the articular surface without deterioration of fixation rigidity.

This study is based on the biomechanical analysis of femur bone using Finite Element technique. Real life activities are taken as boundary conditions and the weight of a person is considered as load for walking, standing and jumping. For biomechanical analysis, three-dimensional CAD model of human femur bone is modelled from MRI/CT Scan data using ITK-Snap software. Pre-processing and post-processing operations are done using HYPERWORKS whereas the solver is NASTRAN 10.0. Analysis is done using three materials- natural bone material, AZ31 (magnesium alloy), CP Ti (Commercially Pure Titanium Alloy). Comparative study shows that CP-Ti material generates minimum stresses for jumping, standing and walking, which are 5.69, 5.34 and 5.71 MPa respectively. And also minimum displacements for jumping, standing and walking are 0.146, 0.0583 and 0.0623 mm respectively. It is found that AZ31 is the best suited material for Bone implants and as its weight is approximately same as natural bone.

Biomechanics deals with the study of the mechanical aspects of the biological objects. The humerus bone is the longest bone of the upper body. In this study, we apply different loads on the humerus bone fixing the proximal (upper end) and applying varying loads on the distal side (lower end) and note down the displacement and maximum stress occurring at different loads for different materials. From this we come to know about the maximum stress at which the bone fails. Model is prepared using ITK-Snap software. MSC Patran software is used for pre processing and post processing, whereas MSC Nastran is used as solver. Analysis is carried out for three different material, natural bone, AZ31, and CP-Ti. It is found that at 85 N natural bone fractures at middle portion of the bone (Deltoid Tuberosity). Bone implants made up of AZ31 materials will be absorbed by the body and no further surgery is required. The stress and displacement are comparatively minimum for this material and it is light weight as compared to CP-Ti. The manufacturing cost is also minimal.

Objective Obesity induced by a high fat diet is associated with chronic up-regulation of inflammatory cytokines which stimulate osteoclast activity and bone resorption. However, the role of high-fat diet on bone-implant connectivity has not been studied in detail. In this study, we investigated whether a high-fat diet (HFD) affects bone implant connection (BIC) in periimplant bone. Methods Twenty female Sprague Dawley rats were divided in two groups: 1) Control rats were fed with normal chow and titanium implants were integrated into tibial bones at the end of 3rd month and no treatment was applied 2) HFD group; rats were fed a high-fat diet (42 % of calories as fat), then the titanium implants were integrated into tibial bones at the end 3rd month. Following surgical integration of the implants, the rats were fed with control and HFD diets for 3 months. After the 6 months experimental period all rats were sacrificed and the implants and surrounded bone tissues were collected and the BIC was assessed histomorphometrically after the non-decalcifiing histological methods. Bone implant connection was detected with the ratio of the implant surface directly connected with the peri-implant bone tissues to the total implant surface length. Results Histologic analysis showed that HFD was not impaired BIC (p>0.05). Conclusion In conclusion, within the limitation of this research, HFD did not effect the BIC rat tibias (Tab. 2, Fig. 2, Ref. 26). Text in PDF www.elis.sk.

Hydroxyapatite (HAp) is most common calcium phosphate ceramic that is used in biomedical applications owing to its chemical composition, which is similar to human bone and teeth. Hydroxyapatite can be synthesised using chemical precursors, especially calcium and phosphorus, using various methods including, dry, wet, thermal, or a combination of these methods. Instead of using chemical synthesis, HAp can also be extracted from natural sources, such as animal bones and scales which are rich in HAp content. Different synthesising methods result in different morphologies, sizes, and phase crystallinities. The concern of achieving a nano-sized HAp has attracted a great deal of attention owing to the human bone HAp is in nano-size range, and the nano size HAp has excellent clinical performance compared to micron-sized HAp. Furthermore, production of nano-size HAp improves cell proliferation and cellular activity in bone growth, which makes it more suitable as biomaterials for bone implants. Thus, various parameters were studied to achieve a composition of HAp that is like the HAp in human bone and teeth. This review summaries various methods of synthesising the HAp, which includes dry, wet, thermal, and a combination of these methods.

Bone implants are susceptible to postoperative infections. Immobilization of antibiotic-loaded microparticles on implants is an effective approach to addressing this problem. Immobilization methods reported in earlier studies frequently used special or potentially harmful conditions. Therefore, the present study explored a new method to immobilize poly(lactide-co-glycolide) (PLGA) microspheres on bone implant materials. PLGA microspheres were prepared by an emulsion method using polyvinyl alcohol (PVA) as an emulsifier. The microspheres were immobilized on two commonly used orthopaedic biomaterials [hydroxyapatite-coated titanium (HA-Ti) and poly(methyl methacrylate) (PMMA)] by dispersing on the surface followed by vacuum drying. Microspheres were retained stably on both materials even after immersion in phosphate-buffered saline for 12 d. Pretreatment of microspheres with sodium borate (i.e., an eliminator of hydroxyl groups of PVA) substantially reduced their retention on HA-Ti, but only moderately reduced their retention on PMMA. This suggested that the binding of the residual PVA on the microspheres to the HA coating is the dominant contributor to their immobilization on HA-Ti, whereas other forces contributed substantially to their immobilization on PMMA. Microspheres containing ciprofloxacin (a water-soluble antibiotic) and triclosan (an oil-soluble antibiotic) were immobilized on HA-Ti and PMMA, respectively. They effectively killed adjacent bacteria. These results offer a simple and versatile method for immobilizing drug-release microspheres on some important bone implant surfaces.

Biomaterials with better osteogenic capacity, rapid osteo-integration, and higher mechanical strength are undoubtedly preferred for successful bone implant development. A porous sodium hydrogen titanate layer was formed on Ti metal by NaOH treatment, and the Na